Electric projector



(No Model.) 4 sheetssileet 1. J. J. WOOD.

ELECTRIC PROJECTOR.

No. 407,914. Patented July 30 1889.

f1 1% I NVENTORI mJ-S (No Model.) 4 Sheets-Sheet 2. J. J. WOOD.

ELECTRIC PROJECTOR.` No. 407,914. Patented July 30, 1889.

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J. J. WOOD. y ELECTRIC PROJECTOR.

No. 407,914. Patented July 30, 1889.

IN VE NTOR:

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(No Model.) 4 sheets-sheet 4f. J. J. WOOD.

ELECTRIC PROJECTOR. No. 407,914. Patented July 30, 1889..

WITNESSES: I NVENTOR:

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UNITED STATES ATENT OFFICE..

JAMES J. WOOD, OF BROOKLYN, NEV YORK.

ELECTRIC PROJECTOR.

SPECIFICATION forming part of Letters Patent No. 407,914, dated July 30, 1889.

Application led October l, 1888. Serial No. 286,919. (No model.)

To all wtmn it Duty concern:

Be itknown that I, JAMES J. VOOD, of Brooklyn, Kings county, New York, have invented certain new and useful Improvements in Electric Projectors, of which the following is a specification.

This invention relates to projectors used for concentrating by means of a concave mirror the rays of light from a focussing electric arc lamp, and directing such rays in approximately parallel direction in order to project to a distance as intense a beam of light as possible. Such projectors are used as searchlights on board vessels and for military purposes, and as head-lights for locomotives and steamboats.

Marine projectors or search-lights have been made wherein a focussing electric lamp is inclosed within a casing containing a parabolic mirror, said casing being hung on trunnions on a transverse axis, so that the beam of light projected from the mirror may be thrown either directly forward or swung upwardly or downwardly. The trunnion-bearings form part of a U-shaped frame, the baseplate of vwhich is mounted to swivel on abase which is fastened to the deck of vessel. By means of this swivel the projector may be rotated in order that the beam of light may be caused to sweep the horizon.

My invention constitutes an improvement in the construction of such marine projectors, and is also in part applicable to head-lights wherein the projector-casing is mounted on a base through the medium of a swivel,where by it may be rotated in a horizonal plane.

My invention relates, chiefly, to improvements in the manner of connecting the conducting-cables or circuit wires or leads which conduct the electric current to the arc lamp, the object of my invent-ion being to so arrange these leads that they shall be out ot' the way, and consequently free from liability to accidental injury, and to prevent the twisting oif of the leads by means of the rotation of the swivel or pivot members of the projector.

My invention also comprehends other im` provenients, as will be fully hereinafter described.

Figure l of the accompanying drawings is a front elevation of a marine projector or the apparatus in horizontal section on the line 3 3 in Fig. 2, partly broken away. Figs. 4 and 5 are enlarged detail sections of one of the truunion-connections of the proj ector-casing, each view being a section on the likenumbered line in the other. Fig. 6 is an enlarged sectional view of the switch or cut-out on the front of the base cut in the plane of the line (i (3 in Fig. 2. Fig. 7 is a vertical transverse mid-section of a head-light embodying part of my invention.

I will first describe the marine projector or search-light shown in Figs. l to o', inclusive.

Let A designate the base, which is fastened to the deck of the vessel or to other suitable foundation; B, the U-shaped carrying-frame mounted thereon and swiveled thereto; O, the4 proj ector-casing -mounted on lateral trunnions borne by the frame B, and D, Fig. 2, the focussing electric-arc lamp within the proj ector-casing. This electric lamp D is of peculiar construction, as will be apparent; but its construction is not claimed in the present application, being made the subject-matter for another application for patent executed by me coincidently herewith. Its characteristic feature is the arrangement of the carbons in front of the regulator-casing, instead of above it, so that the arc is formed in front of the casing and much lower down than was possible with the prior constructions of focussing-lamps. By means of this construction of lamp I am enabled to greatly reduce the size of the proj coter-casing, so that it need not extend downwardly any farther than is necessitated by the size of the front or rim of the parabolic refiector E, whereas heretofore it has been necessary to construct the casing with a deep downward continuation or pocket, extending a considerable distance beneath it, in which to place the regulator-casing of the focussing-lamp. My improved form of lamp not only avoids this disadvantage, but also, by bringing the greater portion of the Weight of the lamp mechanism to the rear of the reiiector, it serves to countcrbalance the weight of the reflector, instead of having itself to be 4counterbalanced by the iitting of idle coun- IOO ter-weights or ballast into the upper part of the projector-casing, as has heretoforel been necessary.

For a further description of the construction of this improved lamp reference is made to my said application.

Except in the particulars herein described, the general construction of the apparatus, including that of the projector-casing, reflector, front glass, the rear door, the swiveled U- shaped frame and the base, is the same as in projectors of this character heretofore made, and does not require particular description.

The projector-casing has its trunnions (lettered d and a) made hollow, the left-hand one a (on the right in Fig. l) serving as a means for admitting the conducting wires or leads, as shown in detailj in Figs. A and 5, andthe one at the right (lettered a,) being utilized as a camera obscura in order to aid in adjusting the arc to the correct focus of the mirror, as heretofore, it being understood that the pivotal axis of the proj ector-casing intersects the focus of the reflector, as clearly shown in Fig. 2. The trunnion a also is provided with an operating-handle F, Fig. l, the metal boss of which embraces it and is clamped firmly to it, so that by turning the handle the projectorcasing, which is nicely balanced, may be turned with ease to any inclination. A setscrew c', is provided for clamping the trunnion, in order to hold the projector rigidly at an;7 angle. The proj ector-casing is so balanced that its center of gravity is very slightly below its pivotal axis, so that after having been deiiected it will upon being released return automatically to a level.

The U-shaped frame B consists of a circular or disk-shaped bottom plate b and two curved arms c c, projecting outwardly and upwardly therefrom and formed at their upper ends with the bearings d d for the trunnions a ct.- The bottom plate Z9 rests upon a corresponding disk or plate e, forming the.v

top of the boss A, as best shown in Fig. 2.

The central portion of this top plate projects upwardly in the form of a tubular boss f, which forms a loose fit With a hub or bearingboss at the center of the bottom plate b, a nut f being screwed on the projecting end of this boss to confine the bottom plate b down in place against the top plate e. The construction thus described constitutes a swiveled connection between the frame B and the base A. This swivel I will designate by the letter G.

On the base A, and preferably on the front thereof, is mounted a cut-out or electric handswitch H for short-circuiting and thereby extinguishing the lamp. The construction is best shown in Fig. 6, where I I are the respective positive and negative binding-posts,

to which the terminals of the external cir-l cuit-'wires are to be connected, and which areiixed to metal plates g g, which are fastened to the cast-iron shell of the base A by means of screw-bolts Z l, as clearly shown, being inmetallic connection with the binding-posti.

This switch-plate .I will thus form ashort circuit between the two binding-posts, thereby cutting out the lamp. In Fig. l this switchplate is shown thrown down, so as vto bring the lamp in circuit.

The respective conducting cables or leads K K are connected the one to the positive and the other to the negative binding-post by being clamped between plates t t', which are fastened by the screws Z l on the inside of the base A, the screw-threads engaging the plate t. They are thence carried out through the hollow pivotal boss f of the swivel G, on emerging from which they pass up along one of the arms c of the U-shaped frame B,

being fastened into the angles .formed by the junction of the rib and web of this arm, and thereby brought out of the way, where they are protected from i-njury. They are fastened at intervals by pins@ i), which are driven tightly into holes drilled transversely through the rib of t-he arm c, leaving` both ends projecting, and these projecting ends are bent down to embrace the cables. At the top of the arm the cables pass off at either side, and, being looped around the exterior of the trunnion-bearing, are thence carried in. through the hollow trunnion 'a to the interior of the projector-casing C, wherein they are led to the binding-posts on the top of the regulatorcasing of the electric lamp. It will thus be observed that the leads are carried through the pivotal axis of the rotative j oint-s or connections in both the swivel G and the trunnion a, so that in the case of any rotative movement of either of these parts the only disturbance of the cables is the slight twist thereby imparted to them, which is practically insignificant.

The cables are quite out of the way and protected against accidental injury, being so arranged that they cannot foul either with the person of the operator or with any of the appurtenances about the deck of a vessel. There is hence no danger of their being accidentally torn or broken, and thereby causing the formation of an arc which might occasion a fire.

The only danger to which the cables are subject is that of being twisted off by the undue continuance of the rotative movement imparted either to the swivel G or trunnion a. To prevent the possibility of this, I provide stops on the respective rotative parts, which by their abutment limit the rotative movement, and thereby prevent the rotation in any one direction being continued so far as to rupture the cables. In the construction IOC IIO

' and 3.

shown these stops are so arranged as to prevent more than halt a revolution in either direction from the normal position of the apparatus; but in case a greater or less range of movement is preferred this limit may be varied by a corresponding change in the arrangement or construction of the stops.

The stops for limiting the rotative movement in a horizontal plane consist of a lug or projection m on the under side of the plate b and an up wardly-proj ecti ng lug n on the upper side of the plate e, the two being relatively arranged so that one shall come into the path of the other upon the rotation of the swivel, and being arranged at diametricallyopposite sides when the apparatus is in the normal position, as clearly shown in Figs. 2 Upon the rotation of the frame B in either direction the stop m will, upon the completion of approximately halt a revolution, st-rike the stop n and thereby arrest the movement. "With the construction shown the sweep of the projector in a horizontal plane is an entire revolution, less only the angular thickness of the two stops m n. In practice for ship use the stops are so arranged that they come into play when the axis of the light is turned att, and the projector being arranged on the central line of the vessel and forward of the masts and smoke-stacks, the inability to make a complete revolution is practically no disadvantage, since the axis of the beam of light can be thrown so nearly directly aft as to be partially intercepted bythe masts or smoke-stacks, and there would obviously be no advantage in being able to direct the light aft against the middle of the masts or stacks; hence all the available horizon can be swept with the projector constructed as shown. A similar arrangement of stops is applied to the trunnion a., as shown in Figs. 4 and 5, where p designates the lug orwing cast on the trunnion, and q designates the lug or wing cast on the bearing d of the trunnion. These stops will not abut until the projector-casing is swung so far on the trunnions as to be inverted and direct the light backward-alimit which is beyond that which is necessary in the practical use of the light. The stops are chiefly useful to prevent the proj ector-casing being swung around the wrong way after being turned up for cleaning, thereby unduly twisting the cables. y

In order to adapt the search-light for use as a head-light, for which purpose the beam of light should be thrown directly forward in an invariable direction, I provide a lock or catch for holding the swivel G rigid in the normal position, the projector-casing being held rigid by means of its set-screw c. This lock may be variously constructed, one example of which is shown in Figs. 2 and 3, where a locking-lever L is pivoted to the rear of the base A, with its upper end engaging a notch o", formed in the periphery of the plate b, and the lower end of the lever projecting downwardly andoutwardly into position to be operated by pressing the foot against it in order to release the lock. The lever is normally pressed outby a leaf-spring s beneath it, and its upper armis steadied by entering between lugs r fr', which resist the transverse strain in case an effort is made to turn the swivel while it is locked. l Then it is desired to sweep the horizon with the search-light, the operator will press with his left footagainst the lever L, thereby releasing the lock, whereupon he can turn the projector to any desired position by means of the operating-handle F.

Fig. '7 shows my invention applied to an electric head-light suitable for locomotives and for ships. In this iigure the lamp is omitted, being the same as in Fig. 2. In this lconstruction the frame B of the preceding iigures is omit-ted, the proj ector-casing C being mounted directly on the base A, and connected thereto through the medium of a swivel G, so that it may be rotated in either direction in order that the rear of the casing may be made accessible, it being usual to arrange head-lights close in front of some obstruction, such as the smoke-stack in the case of a locomotive head-light. As the lamp is trimmed and adjusted through the door in the rear, the importance of this swiveling of the casing whenever there is any obstruction directly behind the head-light is manifest. The leads K K pass from the base A up into the casing C through thehollow pivotal boss f of the swivel, and the swivel is provided with stops m fa, as before described, toprevent undue twisting of the Wires. Normally the lock L holds the head-light in place and keeps it from turning on the swivel. rllhis lock is constructed of a spring-bolt carried by one member ofthe swivel and its'end enteringasocket in the other member, an exterior knobbeing applied by which to operate the bolt. l

Fig. 8 shows an improved means which I have devised for supporting the parabolic retlector within the proj ector-casing. Difficulty has been found in adjusting the reflector so as to bring its focus exactly into the pivotal axis of the projector-casing when the latter is h ung on trunnions, or into exact position relatively to a camera obscura at the side inthe case of a head-light projector, such as is shown in Fig. 7. To facilitate this adjustment, I mount the reflectorl in the casing by means of brackets, which engage by means off-screwclamps the periphery of the reflector, and are thus adjustable relatively tothe casing in longitudinal direction. This enables the reflector to be lirst placed with its focus on the proper line and subsequently fastened in position by adj Listing the brackets to it and clamping them in place in thecasing.

In the construct-ion. shown four brackets are employed; one of which (lettered w) is shown in Fig. 2 in oblique elevation, and on a larger scale in Fig. 8 in longitudinal section. This bracket consists of an L-shaped plate with a slot in one arm engaged by a screw passing through the projector-casing and screw- IOO IIO

ing into a nut, which is held from turning by being confined in a longitudinal recess or guideway on the inner side of the bracket. The front of the reflector is flanged outwardly, and the flange is clamped to the front of the other arm of the bracket by means of a screw y. Sufficient freedom of motion is allowed at both the screws to permit of the requisite adjustment for compensating for any variations that may occur in practice in the dimensions and focal points of different reflectors.

I clailn as my invention the following defined novel features, substantially as hereinbefore specified, viz:

l. The combination, with a projector-casing, of a base supporting it and aswivel-joint between the base and casing having an axial opening, an electric lamp within the casing, and the ci rcuit-leads thereof passing from the base through the axial opening in the swivel and-into the casing, and stops on the respective members of the swivel adapted to limit the rotation of the casing on the base, and thereby prevent the excessive twisting of the leads.

2. The combination, with a proj ector-casing, of a base supporting it and aswivel-joint between the base and casing having an axial opening, and stop projections on the respective members of said swivel located normally diametrically opposite one another, whereby the rotation of the casing on the base is limited to half a revolution in either direction.

3. The combination of a projector-casing hung on trunnions, one of which is tubular, a supporting-frame having bearings for said trunnions, and stops to limit the rotation of the easing on said trunnions, with the circuitleads entering the casing through said tubular trunnion.

4. The combination, with a projector-casing and reflector therein, of a fastening for the reflector, consisting of clamping-brackets engaging the periphery of the reiiector at intervals around its circumference and connected to the casing through the medium of a JAMES J. WOOD.

NVitnesses:

ARTHUR C. FRASER, JNO. E. GAVIN. 

